Serving head



July 22, 1941'. G. E. PHILLIPS- SERVING HEAD Filed July 20, 1940 2 Sheets-Sheet l y INVENTOR l m70 wwf M MMM July 22, 1941. G. E. PHILLIPS SERVING HEAD Filed July 20, 1940 2 Sheets-Sheet 2 INVENTOR Patented July 22, 1941 gGeorge E`.-Phillipsl,y Leetsdale,-Pa.,` assignor to Nationalv Electric Products Corporation, a cor- .poration of Delaware Application July 2o, 194o,ser'ia1No .34s,643

claims.A (01.5743) Y This invention relates to a server head for use in the wrapping of cores,`such asthe cores of inlSulated electrical conductoraand is a continuation-in-part of -rny application 'Serial No. 211,551 filed Jun'e 3, 3.938.'v

It is to Vbe understood that the' serving head hereindisclosed forms part of a complete appa-ratus'primarily purposed to wrap a close helically Woundic'overin'g jacket of'threads around a conductor core -as Jit travels longitudinally,`

through A'the vWrapping instrumentality. The core which is' Wrapped-may belofi,anyf'desired-'simplicity `or complexity.' That'- is', it may be a simple, solid or stranded, metallic conductive element; it may be anassembly of conductive ele-- "ments and filling and spacing str-ucturefas in the "assembly'of a nonmetallicsheathcable; or it maybe as is more usual Val metallic conductive element surroundedby an enclosing sheathof vulcanized or unvulcanizedfrubber or analogousv deformable linsulating' material; The thread of thread as they are progressively'exhausted'by f application of the'threads to the core. Y Itisalso A taken. f I

i y-Becausef ofY technical considerations and manuffacturing economy,` it isdesirableythat the-cops,

may be vany-:twistedor untW-isted lament offcottony-paper,"Rayor1, Nylon",ror other suit:

lable lamented material.

--The serverhead in 'which 'my-'invention resides is mounted for rotation `about the 'core as the cor-e travels longitudinally, and-the server head carries a plurality of bobbins which mount Y `vvound upon the core` lThe thread or threads from-each package pass `from it to an appropriate position-on the travelling core.: being Wound thereon as the server head rotates around the core. It' is'important that f thethreads be applied to the core under tensiorn'so that they will lie smoothly thereon in a firm enveloping jacket or covering. t is also important, and this is particularly true if the 'core includes a sheath of 'unvulcanized rubber; that thetension upon the One reason for` threads should not be too great. exerting a moderate, though adequate, tension on cops or packagesfof the threadlwhich is to Vbe v the threads is to avoid breakage of the threads; y

`andthe other and more exacting reason is to vprevent the threads from cutting into the substance of the-core, such as a sheath of unvul-V canized rubber, because of excessive tension.

vIn the organization of -my server'head, certain of thev tensioning elements serve as trips to trip xa' 'latch controlling the operation of the head,

and those 'elements are supported by threadsY passing .from the bobbin-carried packages to the core. It isA importantin the operationV `of the vserver head that the requisite light tension be maintainedapproximately uniform at all times in. spite ofl the decreasedweight of the packages `of tensioning -means to each other, that the important that the tensioning elements which are Asupported by the Vthreads passing to the core should not fail of their support due to loosening of the Vthread as it tends more freely to unwind When the packages become lighter, but that such support should failand permit an element of such sort to trip the latch, arresting rotation not the server head only when ithethreadrwhch supportsit becomes discontinuous by breakage or by exhaustion ofthe package 4iromfwhich it is or packages, of thread be Wound inmultipleso that a plurality of threads are vtaken "simultane- 'ously `from each of them, tor be l'a'id closely sideby-side on the conductor core in the wrapping operation. Itis important that these threads should not only be .applied under tension of suitable regulated Avalue, but thatthey 'also should be so'fspread and-arranged' in movementv ofeach group of. threads to l the core that the -threads are laidaCcur'ateIy, Without either gaps or overlapping. "In operation of the server Vhead the lines of thread passing from the thread-supporting tensioning members to the core, will ormrdiierent angles -With the longitudinal axis of the corein accordance With the desiredangle which the threads are to form With that Ylongitudinal axis when they have been laid. VI'have provided a director instrumentality organized to have edge contactfwith groups of threads -passngfrom the thread-supportingftensioning members to the core, soto spread and arrangethe threads that they come to appropriate position with relation to each other on the'core; and haveso organized theimounting of that 'director instrumentaiity that' its-edge Contact wit "the groups of threads maybe 'maintainedin dilierent angles formed with the longitudinaraxis of the core by the groups of threads passing .to thecore.

fIhave. provided in my server., head an organization of4 tensioning meansfcapable of keeping the reaches-ofthread passing from the packages of thread to the core under constant and moderate tensioning during consumption of the packages. I havev also so, adjusted the organization thread-supported tensioning members which serve also as trips for the server head, act to :perform thatfunction only under appropriate circumstances.

In the accompanying drawings Fig. I is a detailed fragmentary elevation partially in vertical section showing the bobbin and bobbin-mounting of a package of thread, and illustrating application of multiple ends of threads from such package to a conductor core.

Fig. II is a schematic plan View ofthe structure shown in Fig. I.

Fig. III is a fragmentary detail elevational View on an enlarged scale, showing one of the threadsupported tensioning elements of the server head and the inclined track on which it is supported.

Fig. IV is a cross-sectional view through the track upon which the said thread-supported tensioning element moves, showing the tensioning element in end elevation.

Fig. V is a longitudinal sectional View through the said track and tensioning element takenln the plane of the section line V-V of Fig. III.

Fig. VI is a longitudinal sectional View 'taken in the plane owFig. V and showing the same structure as in Fig. V, butillustratinga diierent position of the tensioning'element, and the-effect of such vdifferent y position in maintaining lmoderatetension on the threads.

Fig. VII is a schematicy plan View ofthe server headV assembly.

Fig. VIII is a side elevationpf athread-supported tensioningmember and thetrack upon which it moves, corresponding to the showing of Fie. V, Ybut illustrating-1a slight modification; in the structureV of the tensioning member.

Fig. IX is a view corresponding to Fig. YLand taken on the section line IX- IXpfFig XIII,

. showing the modified gfor m of tensioning member in end elevation. l

V.Fia X .isaluueitudualgsectioual.View through positiunrof-the;teuSiguinefmemberiandithe@condition of the Vthread which supports it.

In, the -drawin gs, 1-reference numeral ,Il designantesV a. carrier Platform; rotatablyfmeuntedabout a hollowspindle 2 throughewhich abolie, such theiuunduutOr- Qore AY-lgneitudnallntravels. the carrier here eipluralitytohbpbbins; .eanof Vwhich includes@ .vertical post. Sfithreaded .in the `A gbubbnespindle 4 Which is free `to rotate .0n the post 3 Lcar-ries Asquaredhubs 5 which engage thetubular core, 6 0f a Cop, 0rDaCkageIBarredhy thebubbn: `{Ifhe Aluoluluiu mounting includes .aV nut .l rigidlytonnected with the .post 3i and Athebeari.ng. plate, 8 which is fixed tothe sleeve 4. 0 @tate-therewith and which rests upon the uppersurface of ,the

nut. The nut 'I as arnriuriting` element, i r 1 cooperatiun with the plate 8 and undertheweight lof the bqbbin-carried paekage, determines the frictional resistance which is opposed` to rotation of the bobbin in unwinding threadfromthe Abobbin-carried package. `Itis important that the friction opposing unwindingrotationof the bobbin shouldinotbe greatbut i`t is also important that it should not be reduced to a minimum. The

importance of moderate regulated friction inthe bobbin mounting will be explainedindetailin connection with the functioning of ot er elements ofthe serverhead assembly.

Threads `from each-of the Vbobbin-carrived packages B extend inV reaches C .from the packages to the Vcore by way of suitabletensioningland directing members. `The tensioning. assembly Vincludes inclined tracks 9 in the1 form .0f liat barsmounted on the carrier structure Igbetweenythebobbins,

and extended upwardly and inwardly :toward ther amarsi to move them downwardly and outwardly thereon.

As above noted, each of the tension members has a secondary function in addition to its tensioning function. When any one of the members IU falls because of breakage in the reach of thread Yby which it is supported, or by exhaustion of the package from which that thread comes, it is moved outwardly and downwardly to trip a latch interrupting the operating connections of the server head and causing the actuation of a brake to bring the head immediatelyto a stop. Because of this secondary function of ithe tension members, it is important that they should-not so move on the bars or tracks 9 asto producean undesired stoppage of the head. It is also :important that if operation of the server head should be arrestedby breakage in thereach of thread associated with one tension membenor-y by exhaustion of the package from which Vthe-tlnead in that region is taken,stoppage.of themachine shouldgnot result in unwindngthe -threadfrom all the other packages. Such general unwinling would. require unnecessary reorganizationI of ,the server head requiringthe cutting of lslack;andrethreading from all the packages.

The moderate friction provided in the mountings for the several bobbins, `and the structure of the tension members cooperatein preventing both undesired stoppage of the server headand undesired fall of all thetension members when operation of the head is intentionallyarrested.

Referring particularlyto Figs. III to VI inclusive of the drawings, the tensioning memberdllis shown as of generally tubular form to embrace the bar 9 which provides its track and has outstanding at one edge a flange Il which performs thetripping function when thetension member falls. In mounted position of the tension memben there vare spaces I3 lyingbetween the sides of the A bar 9 and the side walls lI4 of the tension member. One of the side walls has in it ahole ISL-andthe other has a hole IIi` of greater s ize;t l ian the hole I5, with its lower edge aligned with lower edge of the hole I5, but with its upper edge staldllgin theassembly at a higherA level than the upper edge of the hole I 5.

The reach vof thread C is threaded vthrough the holes I5 and I 6 of the tension member, vand through the hole 'II in the -bar or track A9. The tension member is therefore supported bythe reach of thread pinched'between the upperedges of one, or both, of the holes I5 and I6, andthe lower edge of the hole `Il in the bar. `In normal operation of the server head, with the` thread passing uninterruptedly from its, packagesto the conductor core,.the tension member is supported Vonly by contact with the thread attheupper edge of hole I5. If, however, there is undue slackness of the thread, caused by it unwinding too rapidly from itspackage, the tension member IIImoves on its track enouglito causer the uppexmedgeof holeIB `alsoto rest uponthe thread. This double contact, andthe tendency forthe tension member to move downwardlyand outwardly,re- `solves the ,slack of thelthread kinto a double rloopfa. loop being vformed -in the space I3 on -each side of the bar ontrack `9. The pinching effect thus created exerts a braking friction'on the thread, maintaining the reach of threadtaut lby'tending to retard passage of the thread to its point of application on the core.

`l Assuming that operation of the serving head is arrested, either by intent or by "exhaustion or breakage ofthe thread forming Ythe supporting between an element connected to turn with the.

bobbin spindle, illustratively the bearingplate 8, and a non-rotatable mounting element, illustratively the nut 1. It is a simple matter in assembling the server head to use a nut which presents to the bearing plate a surface of such area as to give the desired frictional resistance, and to replace it with a nut of like material, but having a contact surface of greater or lesser area, if it should Iappear desirable to develop a greater or ylesser frictional resistance in the bobbin mounting. Typically, the contact surfaces of the bearing plate and the nut are both smooth, hardened steel,` but may either or both be of a different metal if so desired.

The friction in the bobbin mounting being thus tension element, the slack in the reach f thread extended from the package to the core does not become so great as to permit the tension member in its downward loop-forming movement substantially to unwind the package. In this action the frictional resistance and slack-absorbing characteristics 0f the tension member tend to prevent substantial unwinding pull on the bobbin-carried package, while the slight frictional resistance to unwinding rotation in ythe bobbin mounting resists such slight unwinding pull as there is.

A modified form of tension member is shown in Figs. VIII, IX and X of the drawings. That tension element Illa. is generally similar to the tension element I0, and carries a trip-operating flange I'Ia identical with the ange YI1 of the member I0. Instead of the holes I Iand I6, it has, however, slots I5a and Ia cut upwardly unequal distances from the lower edges of the two sides I4a, of the member. 'Ihis is the form of tension member specifically disclosed in my lprior application, referred to above. The form of tension member previously described has one Yimportantv advantage over the modified form of tension member. In winding the packages oi thread in multiple, the groups of threads are frequently knotted together at their ends. When a package is exhausted it is more likelyk that a knot will catch at the'lower edge of one of the slots ISU. and I6a in one of the spaces I3a than -at the edge of one of the circular holes I5 and I6. As the catching of a terminal knot in the tension member holds the tension member against downward and outward movement on its track, and thus prevents stoppage of the server head when a package is exhausted, it is an effect which should be avoided.

Itis; ofcourse, possiblevtof-u'selthe server head to wind-single threads fro'm single-woundf-spools,

and by?` the termI epackagesfl IlV intend to include such 'spoolsias Well-las those" whichl'are' wound kin multiple. `VAssh'owrhhowever, l"e'ac'h reachC of threadpaS'Sing to'lthe conductor coreV and-*wound thereon contains a-plurality of individual threads,

Y Wound ini multiple .inl mak-ingl upa package and VVunwound as a*v unit from-it;- f In serving the core,

it is necessary that they lie side-by-side on the core iniclose `contact witheach other-land. without overlap. Todo this Il-'provide thread-spreading Y and -thread'arrangingmeans @functionally f placed between each tensioning member andthe core,

appropriately/to contact the-.threads lofleach reach lin theirpassage. The iirstele'mentof each Y mounted `inclosely `spaced p'ositi'onf on each` of the bars 9 t0 project from the'sidelof the Ybar which is fr functionally adj acent the core.' #These pins-1 have smooth -rounded surfaces, `and each group'of threads forming areach is passed over one and under the other-pin of Valpar, as shown in Figs. I and I Iof the drawings.

The most important element of'r the arranging organizationfis a director head 120, which has a rounded 'thread-contacting edge. IGroups of threads D, after passing overfand under the pins `-I8 and I9, come in contact withrtheiedgeof the director head and bythat contact aresuitably arranged side-.by-'side, as theyS reach their position on the core, since!theyemayrshiftialongthe rounded edge in response/-to--thepullicaused by rotation of the platform around the spindle through whichv the 'corelpasses The director head is necessarily-.perforatef centrally, -and'- is mounted by a tubular stem 2l lin the upperend ofspindle 2. The director head is vertically adjustable inthe spindle, vertical adjustment being shown as provided by a cooperativel threading of its stem 2| and the socket in which lthe stem rits. In serving the conductor core, the number of individual threads or ends which are applied in a single revolution of the server head platform'determines the angle which. theturns of the applied wrapping form with the longitudinal axis of the core. That anglewith which the threadsare wrapped `follows rearwardly from the core to the edge of'the director Yhead which the threads contact.` It isimportant,'therefore, that the directorhead be vertically adjustable toconform with different angles at which it may be desired to apply the -served Wrapping.- I

The organization of elements herein-'particularly specified, or the functional equivalent of such organization of elements, lis of a primary importance in obtaining accuratey and `efficient operation of a serverhead by Which'served `wrapvpings areapplied to a core, suchxas an Velectrical packages of'thread on the carrier structure, fand means for leading threads fromthe packages to the core;the combinationof Va bobbin-mounting organized' under the weight' of 'the bobbin-carried package to `oppose moderate'frictional re- Vin the yreach ,ofi t hread passingfrom the bobbin- Vbobbi,r1-carriedV carried packageto the core and adapted to maintainapproxmately uniform-tension on the thread.

by opposingto movement ofl the thread increased frictional resistance thefricticn in the bobbin mounting decreases with decreased vWeight ofthe package as the threadnnwinds therefrom.

.2. In a server-head for wrapping a jacket of threads upon a conductor core as it travels comprising acarrierstructure rotatable around the conductor core, a-pluralityof bobbins carrying packagesof thread on the carrier structure, and

means for leading; threads from the packages to the core; the, combination of a bobbin-mounting organized under the lWeight of the -bobbin-carried package to Oppose moderate `frictional resistance .to rotation of `the bobbin f or unwinding thread .from the package, anda tensionmember in the vreach of .thread carried from the bobbin-carried `package to the core formed and arranged to resolve slackness of threadmoving therethrough into conned loops of a length proportioned to theslackness ofthe thread and thus to maintain. Iapproximately uniform tension on the thread byopposing to movementv .of thethread increased frictional resistance as the friction in the,.bobbinmounting decreases with decreased Weight Yof the bobbin carried package as-th threadlmwindstherefrom.

3..In as erver head forwrapping .a jacketof threads upon a conductor'core as it travels .comprising a carrier structure rotatable around` the .conductor core,` a pluralityof. bobbins Acarrying packagesl otthread on the carrierstructure, and means for leading threads from the packages to thecore; `the combination of a bobbin-mounting organized under Ythe weight of the bobbin-carried package tooppose moderatefrictional resistance to vrotation of the bobbin for `u nvvinding thread from the package, and a tension member supported by the reach of ,threadpassing from the bobbin carried package to the coreto exerta to rotation ofthe bobbin forunwinding thread from the package, and a tension member supported by the reach of thread passing .from the bobbin-.carried package to the core and adapted to maintain approximately uniformtension on the thread by opposing to movementof the thread increased frictional resistance as the friction inthe bobbin mounting decreases with decreased weight ofthe A bobbin-carried package as the thread unwinds therefrom; the .frictional resistance inthe bobbin mounting being adequate under all conditions of the bobbin-mounted package to prevent unwindingof threadfrom the said packageunder .the vveight of` said tension member whentheserverhead' is stationary.Y

' 5,1 in aerverj nella for wrapping ajacket of g sistance to yro ta ti n of the bobbin fonunwinding thread `frozrrthe. :packagaan'd a tension member threads upon a conductor core as it travels comprising a carrier Astructure rotatable around ,the conductor core, a plurality of bobbins carrying -packages of thread on the carrier structure, and means for leading threads from the packagesto the core; the combination of a bobbin-mounting organized under theweight of the bobbincarried package to oppose moderate frictional resistance `1go-.rotation o f the bobbin for. unvvinding thread from the package, and a tension member in the reach of thread Apassing from the bobbin-carried package to the core and arranged toresolve slackness of thread passing therethrough into friction-increasing loops of a length proportioned to slackness of the thread and thus tomaintain approximately uniform tension on the thread by opposing to movement vof the threadincreased frictional resistance as the friction in the bobbin .mounting decreases with decreased Weight ofthe bobbin-carried package as the thread unwinds therefrom; .the frictional resistance in the bobbin mountingbeing adequate under all conditions of the bobbin-mounted package to prevent unwinding of thread from the said package under the Weightof said tension member when the server l head .is stationary.

6. In a core-Wrapping assembly composite of a carrier structure rotatable around a longitudinally travelling coreand having thereon a plurality of rotatable bobbins carrying packages of thread; vthe herein describedtensioning assembly organ- `ized in the reach of thread extended from each bobbin-carried package to the coreand constructed to counteract'the slackness of thread caused by decreased Weight of the said bobbincarried package as itis unwoundby forming one friction-increasingV loopwith slight` slackness in the .thread and anadditional friction-increasing loop with greater slackness in the thread.

7. In a core-wrapping assembly composite of a carrier structure rotatable around a longitudinally travel-ling core and having thereon a plurality of rotatable bobbins carrying packages of thread; thread-tensioning means for each bobbin consistingof an inclined bar peforate for passage of threads from the bobbin-carried package to the core, a Winged member slidable on the said bar and having at opposite sides of the bar threadcontacting surfaces arranged at different levels with respect to the perforation of the bar, by contact with one orbothofwhich surfaces the thread passing through the bar supports the said member against forces tending to move it downwardly on the bar and by selective contact with one or both of which surfaces slackness of the threadis .resolved into one friction-increasing loop with slight slackness in the thread and an additional friction-increasing loopWith greater .slackness in the thread. f

8. vIn a core-wrapping assemblyconiposite of a carrier structure .rotatable around a longitudinally travelling core and having thereon a plurality of rotatable bobbins carrying packages .of thread; the herein described novel threadfeeding organization .consisting primarily of mountings for the several package-carrying bobbins of the assembly each including opposed contact surfaces organized to produce With each other moderate frictional lresistance adequate to prevent lfree-running of the bobbin in the' absence of an unwindingpull on the bobbin-carried package, andthread tensioning means'for each'bob- 'bin consisting of an inclined bar 'perforate for 'passing of threads from the bobbin-carried package to the core, a Winged' member slidableon the saidvbar and having at opposite sides of the bar thread-contacting surfaces arranged at different levels with respect to the perforation of the bar, by contact with one or both of which surfaces the thread passing through the bar supports the said member against gravity and by contact with both of which surfaces slackness of the thread is resolved into one friction-increasing loop With slight slackness in the thread and an additional friction-increasing loop with greater slackness in the thread.

9. In a server head for Wrapping a jacket of threads upon a conductor core as it travels comprising a carrier structure rotatable around the conductor core, a plurality of bobbins carrying packages of thread Wound in multiple on the carrier structure, and means for leading threads from the packages to the core; the combination of mountings for the said bobbins organizedk under the Weight of the bobbin-carried packages oppose moderate frictional resistance to rotation of the bobbins for unwinding threads from the packages, tension members in the reaches of thread passing from the bobbin-carried package to the core and adapted to maintain approximately uniform tension on the threads by opposing to movement of the thread increased frictional resistance as the friction in each bobbin decreases with decreased Weight of the bobbincarried package as the thread unwinds therefrom, and a director head adapted for edge contact with the said threads in lines inclined to the longitudinal axis of the core followed by the threads between the tensioning members and the core, by its interposition to spread and arrange the said threads. f

10. In a server head for wapping a jacket of threads upon a conductor core as it travels comprising a carrier structure rotatable around the conductor core, a plurality of bobbins carrying packagesfof thread Wound in multiple on thel carrier structure, and means for leading threads from the packages to the core; the combination of mountings for the said bobbins organized under the Weight of the fbobbin-carried packages to oppose moderate frictional resistance to rotation of the bobbins for unwinding threads from the packages, tension members in the reaches of thread passing from the bobbin-carried package to the core and adapted to maintain approximately uniform tension on the threads by opposing to movement of the thread increased frictional resistance as the friction in each bobbin decreases with decreased Weight of the bobbincarried package as the thread unwinds therefrom, a director head adapted for edge contact With the said threads in lines inclined to the longitudinal axis of the core followed by the threads,y and mounting means for the said director head arranged for adjustment of the director head longitudinally of the core to bring it into edge contact with the threads following lines differently inclined to the longitudinal axis of the core. l

GEORGE E. PHILLIPS. 

